Here's why Hubble Space Telescope is inoperable since June 13
The NASA/ESA's Hubble Space Telescope, which is behind some of the most incredible pictures of distant galaxies to date, is reportedly defunct for the past few days. The Hubble team is now troubleshooting an issue with the telescope's payload computer that was built in the 1980s. This computer is responsible for controlling the telescope's scientific instruments. Here's everything you should know about the issue.
In a statement, NASA said that the payload computer halted on June 13. An attempt to restart the computer failed on June 14. The space agency has deduced that a degrading complementary metal-oxide-semiconductor (CMOS) memory module caused the computer to halt. Meanwhile, attempts to switch it to one of the three backup memory modules on June 16 also failed.
The payload computer is a NASA Standard Spacecraft Computer-1 (NSSC-1) that was built in the 1980s. It is housed in the Science Instrument Command and Data Handling unit of the unmanned telescope that was replaced in 2009 during Hubble's last astronaut servicing mission. The primary function of the computer is to control, synchronize, and monitor the telescope's scientific equipment for longevity and safe operation.
At present, due to the payload computer's issue, all of Hubble's scientific equipment remains intact but has been set to operate in safe mode by the main computer. Thankfully, like all equipment sent to space, Hubble has a backup plan. In the event of a problem, NASA can switch operations over to a second computer with the requisite hardware that's already in orbit.
However, the backup computer and the malfunctioning payload computer share the same bank of four memory modules, each of size 64 KB. Only one memory module is kept operational at any time, while the other three serve as backup. We hope that NASA succeeds at fixing the telescope so we can continue to gawk in awe at Hubble's images of the infinite cosmos.